DR650se FCR Carburetor Conversion

Discussion in 'Australia' started by kezzajohnson, Mar 1, 2014.

  1. kezzajohnson

    kezzajohnson kezza

    Joined:
    Apr 17, 2007
    Oddometer:
    1,763
    Location:
    Cairns - Queensland Australia
    Ok, It's been asked for so I am going to start the ball rolling. Post your experience, ideas, results, queries with regards to installing the FCR flat slide pumper carby on your DR650se.

    Here's mine. An ebay purchase off an '04 YFZ450 quad. It's a 39mm FCR MX and had the features I wanted including the ability to retain the DR650s stock push pull throttle cables.

    I mostly followed the ledgendary mxrob's FCR MX conversion which can be found here:

    http://mxrob.com/mxrob_007.htm

    [​IMG]

    Under the throttle cover, the pulley has the slot for the push cable but the housing is blank need to be drilled and tapped.

    [​IMG]

    Using a 5mm drill bit, I drilled a hole through the housing and then tapped it with a 6mm x 1 mm tap. I then cut a slot with a cutting wheel and dremel to beable to slide the cable in place. I followed mxrobs cable adjustment procedure which worked pretty well.

    [​IMG]

    The only other major adaption was to have an airboot adaptor made up which I had a local engineering shop make up for me from aluminium to dimesions of 54.5mm ID x 58.5mm OD x 26mm long. I then used JB weld to glue/seal the adaptor to the carbys airbox side.

    [​IMG]

    I decided not to drill into the carby to install a vaccum port, instead opting for a raptor fuel tap which is gravity feed. Altough inititially I just ran the standard fuelcock on prime until I got the Raptor fuelcock to instal.

    [​IMG]

    The carby was east to install. First you need to undo your airbox so it floats around and can be moved the make way for the carby. Install the engine side first and a bit of silicone lube on the intake manifold helps. One in place in the intake manifold and the clamp has been tightened, work the airbox boot into place and then bolt your airbox back in to place. Seen below installed but late added an inline filter to fuel line.

    [​IMG]

    I started out with mxrobs recommended jetting and needle but after some trial and error as well as advice from DRsteve and BergDonk, I am down to these settings.

    155 main jet
    40 pilot jet
    85 pilot air jet
    85 starter jet
    35 leak jet
    NCVT needle on 2.5
    Fuel screw 2.25 turns out

    So far so good, I have sorted the backfiring issue I initially had and idles pretty close. I am still playing with the fuel screw adjustment to fine tune things. Do yourself a favour and get a R&D flexible fuel screw. makes fine tuning so much easier and less risk of it backing/falling out.
    #1
  2. DR Steve

    DR Steve Been here awhile

    Joined:
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    Looks like you beat me to it Kezza !

    The idea was to try and put all the FCR jetting info for the DR in one place so it can be a useful reference for others going forward. Currently there is info in the OZ DR thread, the main DR thread, DRridders, BergDonks build, TT and others. Pretty time consuming to sort through all of those to find something useful. OZ bikes seem to need different jetting to the US too.

    As I've found between my '08 and new '13 DR, the settings will be a little different between bikes - even with the same mods.

    My jetting is as follows for the '13 DR...

    MJ 162
    NCVT #1.5
    PJ 40
    PAJ 73
    Fuel Screw 7/8 turn out
    LJ 45
    Starter Jet 65 (not 100% sure on this one)
    ACV blocked off
    FCR MX 39, fully open top airbox, twinair filter, stock header, GSXR Ti can.

    I originally started with the common mx_rob jetting and found it far too rich for conditions here. Lots of testing with a wideband O2 setup led to the selection of the multi taper Honda NCVT needle. A number of other riders have now fitted the NCVT needle with good results.

    This is the only pic I can find of the adaptor I machined up for the conversion. It's posted elsewhere too.
    [​IMG]
    And an installed pic too. I like to put filters on the drain/vent hoses - stops the dust getting in.
    [​IMG]
    #2
  3. BergDonk

    BergDonk Long timer

    Joined:
    Nov 15, 2010
    Oddometer:
    4,026
    Location:
    Snowy Mountains Oz
    FCR Jetting SD5 800m
    Main 150
    Needle NCVT
    clip from Top 2.5
    PAJ 70
    Leak adj 3 T
    Pilot 40
    Fuel Screw 1.5
    Float 9
    Start 85

    Longish story told in numerous posts in the link in my sig. from post #72 page 5:
    http://www.advrider.com/forums/showthread.php?t=646076&page=5

    The NCVT discussion gets going in post #384 here:
    http://www.advrider.com/forums/showthread.php?t=646076&page=26

    Started off more or less with MXRob's specs and with the benefit of DR Steve's identification of the NCVT, I'm now happy with above settings. Although specced at 800 m, its fine at sea level too, and higher. If I didn't have an adjustable leak jet, it likely still be the #35 too. I have some bigger PAJs enroute, and may end up a little bigger there too, but the #70 works OK.

    ACV is operational, the airbox top is opened up more or less like the template and the exhaust is a 041 can with FMF PB header.

    I've also adapted the carb to take the stock cables.

    I have a couple more to setup in the months to come, so it'll be interesting to see where they end up.

    [​IMG]
    #3
  4. kezzajohnson

    kezzajohnson kezza

    Joined:
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    Ahhhhh, that's better. A one stop shop for those in Oz that have done this mod.

    Well the rain here in Cairns let up for once in a long while and weather was ideal to get out and about and finally give the FCR a decent run with a wide range of riding from hilly bitumen ranges to open forestry 4WD tracks to tight single trails.

    Started out the day realising that it didn't like idling until after about 20 minutes riding and getting the engine/carb temp up to normal operating temp. Once warm I bought the idle up a bit and played around with the fuel screw. In the early stages of the instal, I found that winding the fuel screw all the way in didn't really do much, but then following BergDonk and DrSteve's advice to give it plenty of time to warm up first including feeling the fuel bowl for warmth, I had a fiddle with it about half n hour in to the ride. Starting at it's 2.25 turns that I had it on, I found I could turn it in to about 1 and 3/4 before the idle would falter. Winding it back out again, I got to 2.0 turns for it to idle smoothly again, so have left it there.

    All other settings remain the same as my previous post here but my fuel screw is now at 2.0 turns which seems to be pretty spot on for my bike.

    1/2 way through the ride for some reason the idle seemed to drop off during one stop (down to about 1200 RPM) which also coincided with some extra popping and small backfiring on decel on the lead up to that stop, so I screwed the idle screw up to reach the 1500 RPM that is standard for this bike. Not sure if I have an issue with the idle screw working it's way out or something else but no futher issues after that. The power delivery is nice and clean. No surging and power right down low (felt awesome of tight single trail, even with road gearing) I Did 171km of 50/50 road/dirt and achieved 21.85 kilometres per litre- better than I have ever had since the bike was brand new, stock standard on the BST40.

    Having a vapor, I was pretty closely monitoring my engine (oil) temp and it does seem to be running an average of about 3 or 4 degrees warmer across the board but I am not concerned about that. My BST40 was always on the rich side probably making the engine run a bit cooler.

    I still find that whistle a bit off putting as it only seems to do that under acceleration or under load and I have to keep telling myself that it is what the FCR's do and that the slide isn't rattling itself to bits.

    Being a used carby and not having a control FCR as such, I can't really determine whether the vaccum release plate and/or it's seal are at the replaceable stage so I have bought some cheap insurance getting one of these (ebay US) plus a new seal/oring (Show and GO Aus) to go on it. It was advertised as the 'M' but the seller also has the 'Ls', what ever they are off ?

    [​IMG]

    here's the link to Ebay seller: (scroll down the page)

    http://www.ebay.com/itm/271403088616?item=271403088616&viewitem=&sspagename=ADME:L:OC:AU:1120&vxp=mtr

    As we speak, I am still waiting for it in the mail.

    I don't think too many here have had experience with this 'aftermarket' vaccum release plate and it does vary from the genuine item in it's material and also that it doesn't have the recessed halves on other side to what holds the o-ring/seal. Made from Billet 6061 T6 aluminium, I don't think I am going to have to worry too much about replacing it too often as preventative maintenance. So, I'll be the guinea pig and let you know how it goes and if there are any running issues with it, but I don't expect so.
    #4
  5. Lizard of Aus

    Lizard of Aus Team Husky

    Joined:
    Feb 5, 2010
    Oddometer:
    251
    Location:
    Brisbane North
    Outside of Suspension upgrades, the best mod I made to my DR :clap

    Purchased my FCR 39mx direct off MX Rob. I was extremely happy with the results, can't remember jetting specs though. Considering all the options for the BST carb with JD kits, different needles, drilled slides I figured this was the PROVEN performance enhancement that wouldn't eat up my time without lots (some though) of jetting experimentation. Performance Mods to the BST don't really give any great gains like the FCR does.

    Other mods done at time of FCR install was the airbox mod and a slip-on like an FMF (Roosta). I followed MX robs Install instructions and had no issues. One thing to note is to double check the condition of the throttle cables as any small frays or stickiness will impact the FCR much more than the BST.

    Patience is the key to finding a good condition FCR for not a lot of $

    Just my experience.
    #5
  6. Dano85

    Dano85 Dual Sport Rider

    Joined:
    May 15, 2013
    Oddometer:
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    Location:
    SW Queensland, Australia
    Apologies if I sound like an ass-kiss but after all the time BD, DRS, KJ and others have taken to pass on their knowledge of the FCR mod just wanted to say a big bloody thanks to you blokes - it's much appreciated by numpty's like me that need someone to point me in the right direction. :thumbup
    #6
  7. kezzajohnson

    kezzajohnson kezza

    Joined:
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    Glad to see you're happy Lizard of Oz. It's refereshing to see someone that knows what they want and is happy straight up with what they get. Unlike me who never knows what I want and am never happy unless I am changing something or just pottering for the sake of it.

    Dano85, no worries, but I owe it all to Mxrob initially through back and forth emails and then to BergDonk and DRsteve who have helped me with advice and experience to Oz conditions. Like those guys though, I am always happy to share my findings with anyone willing to listen.

    On another note and thinking more about my idle issue mid ride yesterday ( heres the quote:)

    ---1/2 way through the ride for some reason the idle seemed to drop off during one stop (down to about 1200 RPM) which also coincided with some extra popping and small backfiring on decel on the lead up to that stop, so I screwed the idle screw up to reach the 1500 RPM that is standard for this bike. Not sure if I have an issue with the idle screw working it's way out or something else but no futher issues after that.--- Unquote

    I started out the ride with a full tank of premium 95 octane fuel and at sea level. Not long before I had my low idling issue, I refueled the bike (only took 3.85 litres at that stage) but with standard unleaded fuel. I had also reached an elevation of 450m above sea level (according to google earth) when the idling issue raised it's head. At that stage I adjusted the idle up and there didn't seem to be any issues once back down to sea level.

    So any one here think that elevation or fuel type (octane) could affect the carby in this way. BergDonk, you mentioned yours runs fine at sea level but it is set up at 800m above. Do you think that the opposite: i.e setup at sea level could be adversly affected by elevation ?
    #7
  8. DR Steve

    DR Steve Been here awhile

    Joined:
    Jan 21, 2012
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    343
    Location:
    Melbourne, Australia
    We are fortunate, from a tuning perspective, to not have much of an elevation issue to deal with here in Australia.

    I ride from sea level to max of about 1800 M. Most riding is in the 300 - 1200 M range. One setting will easily cover that range of elevation. Temperature variations make a far bigger difference. I aim for a middle of the road tune at 15 - 20 degrees/6-700 M. Leaves a bit of room in either direction.

    Kezza,

    My idle speed does fluctuate a little also. Don't confuse the idle speed with the idle strength. I've found all the FCR equiped bikes I've owned to vary a little in idle speed. The AFR is still constant with a few hundred RPM of fluctuation. I put it down to the difference between having a slide vs a butterfly. I think the butterfly is more repeatable in it's closing. You will only need the closed slide height to vary by a few thou to change the idle speed. My bike, when warm, will happily idle at 1000 RPM if you set the idle that slow. I aim for 1350-1400 RPM.

    Make sure when you adjust the fuel screw that you have the idle speed backed off as much as possible. This will make finding the sweet spot much easier.
    #8
  9. kezzajohnson

    kezzajohnson kezza

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    Awesome Steve. cheers. You have hit the nail on the head because when I noticed my idle drop to about 1200 RPM, I only noticed it because I have a tacho and was watching it. If I didn't have the tacho, I wouldn't have known the difference as there was no roughness, about to die feel about it like the BST carby would have with the revs that low. You've convinced me that there really is no issue because everything else is just spot on sweet. I'll forget about it now and just move on me thinks.:clap
    #9
  10. Dano85

    Dano85 Dual Sport Rider

    Joined:
    May 15, 2013
    Oddometer:
    45
    Location:
    SW Queensland, Australia
    G'day guys,

    I'm awaiting the arrival of my 2nd hand fcr carb for my '09 DR and i'm planning to put new jets through it. I'm not after the absolute perfect set-up more of a 'safe bet' for guys like me who aren't capable of tweaking it to get it spot on. I realize every bike is different so I was wondering if this a reality or am I dreaming? As per my previous post when it comes to carbs and tuning i'm an absolute numpty.

    I was thinking something like:

    155 main jet
    40 pilot jet
    73 pilot air jet
    85 starter jet
    35 leak jet
    NCVT needle on 2.5
    Fuel screw between 1.5 - 2.5 turns out

    For info I have a stock header with grind done, keintech midpipe and gsxr 40f1 can - air box mod to be done on install of carb.

    Any advice would be awesome.
    #10
  11. kezzajohnson

    kezzajohnson kezza

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    Location:
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    Should be pretty close with those settings and good enough to start with. Seems to be a bit of a mix of what we others are running here.
    Show and Go said they list a 75 pilot air as smallest and they only had an 85 in stock when I was after one. My carby had the stock 100 PAJ but I wanted to try smaller. I went with the 85 and it seems ok. The PAJ I am led to believe is the least critical of all. My fuel screw is now at 2.0 turns out.

    Check and recheck the float level is at 9mm. If you need advice on how best to do that, just ask here. I made up a special tool.

    By the way, do yourself a favour and get an R&D flexible fuel screw if you can. I started with the keintech fuel screw and it was a prick of a thing to adjust with hot engine etc and ditched it quick smart. Theres also issues with them backing themselves out and sometimes falling out completely, where as the R & D screw wont do that and is oh so easy to adjust and get that mixture right.

    [​IMG]

    Got mine through MCAS for a pretty good price.
    #11
  12. Dano85

    Dano85 Dual Sport Rider

    Joined:
    May 15, 2013
    Oddometer:
    45
    Location:
    SW Queensland, Australia
    Thanks KJ, i'll definatly order the R&D, looks like a great idea.

    I'm ordering my jets through SAG so i'll go with the 75PAJ.

    As far as the float level if you wouldn't mind giving me a few pointer it would be bloody awesome.

    I can see me opening a can of worms here and will become addicted to trying to fine tune this carb, prepare yourselves for plenty of questions! haha thanks again mate
    #12
  13. kezzajohnson

    kezzajohnson kezza

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    No worries. I followed Mxrobs procedure for checking and adjusting float level.

    here it is here:

    [​IMG]

    Rather than use a square like Rob does (because I don't have one), I made up a measure with an old set of plastic vernier calipers I had laying around. Screwed in place set at 9mm and glued a strip of perspex to it as you can see in the pic below. It is straight and level on the edge that matters. The perspex arm will rest on the bottom of the float and the short arm of the calipers rests on the carby body (float bowl mating surface). I pulled my carby off three times to check and recheck the float level. Not because of any apparent running issues but for a few drops of fuel I was getting from the overflow/drain tube after the bike had been shut down and with fuel turned off. That no longer happens after my third check and finding the float was too high.

    [​IMG]

    Looks pretty rank but works.
    #13
  14. Dano85

    Dano85 Dual Sport Rider

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    SW Queensland, Australia
    Ah KJ your a bloody champion, I have a spare caliper in my reloading room and some perspex in the shed that will fit the bill nicely. Thanks for your help mate
    #14
  15. Dano85

    Dano85 Dual Sport Rider

    Joined:
    May 15, 2013
    Oddometer:
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    Location:
    SW Queensland, Australia
    Hey guys, just trying to order jets from show and go - apparently there are two types of PAJ, does anyone have a part no handy? Cheers
    #15
  16. kezzajohnson

    kezzajohnson kezza

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    They have 2 different styles of PAJ.

    One is 8.5mm long.

    The other is 13mm long.

    I am assuming that you don't have your carby yet in order to remove the PAJ and measure it but if it is an OEM FCR or FCR MX, then the 13mm long one is the one you need.

    I just asked for the 13mm long one in the size I wanted, which in my case was the 85 because that's all they had in stock. The part number for that is
    N424-330-085 (according to their receipt), so I would imagine that you would just change the -085 at the end to -075 if that's the size you are after, or just ask for a 75 Pilot Air Jet 13mm long.

    They told me at the time that 80 was the smallest they list, so I would be surprised if they come up with something different.

    Show and Go website.http://www.showandgo.com.au/ Scroll down home page and look for Sudco catalogue which you can download. Good read and very comprehensive but has everything in there including exploded views of the carby etc.



    Let us know how you go.

    My Vaccum release plate arrived from the States today. Just 2 weeks after I ordered it. Looks pretty good too. Pretty happy with that considering the postage was only $8.80 Australian. I've waited longer for parts ordered in Australia.
    #16
  17. Dano85

    Dano85 Dual Sport Rider

    Joined:
    May 15, 2013
    Oddometer:
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    Location:
    SW Queensland, Australia
    Yep spot on Kezza - got the carb today and checked the PAJ and it was 13mm.

    I'll send them an email and see what I come up with and let you know.
    #17
  18. kezzajohnson

    kezzajohnson kezza

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    Location:
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    :freaky
    #18
  19. BergDonk

    BergDonk Long timer

    Joined:
    Nov 15, 2010
    Oddometer:
    4,026
    Location:
    Snowy Mountains Oz
    I thought I'd add this link here:
    http://husaberg.org/wiki/index.php?title=2001_to_2008_Husaberg_Models_-_Carburation

    and copy this table:
    Taffy's PAJ PJ Map

    PJ 35 38 40 42 45 48
    PAJ 45 55 60 65 75 85 90 95 100 105 110 120 125 130 135 140 145 150 155
    Adj PAJ 0.250 0.375 0.500 0.625 0.750 0.875 1.000 1.125 1.250 1.500 1.750 2.000 2.250 2.500 2.750 3.000

    The content of the above link was largely compiled by Taffy and was where I started when I fitted an FCR on my FE501.

    Its why I wasn't too concerned about not having a #100 PAJ when I first set up my DR's FCR using mostly MXRob's specs. MXRob specs a #100.

    [​IMG]

    In the pic above, left to right is an adjustable PAJ, a needle valve and spring, a #100 PAJ from an FCR MX and on the right, 5 PAJs the same bigger physical size as the adjustable one from earlier carbs like that of a DRZ400E, and sent to me in error. I was after the small ones, like these and copied from the Sudco catalogue, but only down to #80:

    [​IMG]

    Fuel
    I haven't found my DR fussy at all, having run it on Opal, 91, 95 and 98. It does though seem to feel just that bit sweeter on 95, but maybe its a placebo effect, dunno. No ethanol blends for me if at all possible. At my local servo they have abandoned 95 in favour of 98, so I go 50/50 91 and 98 which seems to have the same feel as 95, and I'm pretty sure its a few percent more economical on 95 or the blend than 91 or 98 too.

    Remember that octane is about the speed at which the fuel burns, not about more energy, or being 'cleaner'. Higher octanes burn slower to allow for higher compressions. 98 in the DR probably needs the timing to be advanced to get any value, or the compression bumped.
    http://en.wikipedia.org/wiki/Octane_rating

    Note also that we use RON here in Oz, in the US its different. I thought it was MON, but the above link says its AKI, an average of MON and RON.
    #19
  20. DR Steve

    DR Steve Been here awhile

    Joined:
    Jan 21, 2012
    Oddometer:
    343
    Location:
    Melbourne, Australia
    The above table for PJ to PAJ sizing is a good reference but a functioning ACV muddies the water a bit.

    The PAJ sizing is probably more important than the PJ size as it controls the shape of the fuel curve.
    For example, I've tested a 105, 85, 73 PAJ's all with a 40 PJ. All combos produce the same AFR (once the fuel screw is adjusted correctly) at idle but vary a lot in off idle/trailing throttle. A smaller PAJ makes the top of the curve richer with a lesser effect at idle. You can't richen the fuel screw to acheive the same thing as it will be too rich at idle if you do. It's easy to confuse this area of throttle opening with the needle root dia as they overlap quite a bit.

    For reference, the 73 PAJ I'm using is only a 73 as it's been soldered and redrilled. I was aiming for a 70 but ended up a little oversize.

    On the DR I just use 91 unleaded and don't get any detonation under the worst of conditions. I have tried 95 a few times and don't notice any difference in fuel economy or performance.
    #20